#define _CRT_SECURE_NO_WARNINGS 1

#include <iostream>
using namespace std;

class A
{int _a = 1;};
class B : virtual public A
{int _b = 2;};
class C : virtual public A
{int _c = 3;};
class D :public B, public C
{int _d = 4;};
int main()
{
	D d;
	return 0;
}

//class A
//{
//public:
//	int _a;
//};
//class B : virtual public A
//{
//public:
//	int _b;
//};
//class C : virtual public A
//{
//public:
//	int _c;
//};
//class D : public B, public C
//{
//public:
//	int _d;
//};
//int main()
//{
//	D d;
//	d.B::_a = 1;
//	d.C::_a = 2;
//	d._b = 3;
//	d._c = 4;
//	d._d = 5;
//
//	return 0;
//}